Wireless devices can now handle voice and/or data, allowing simplex and/or duplex voice calls, video calls, text messaging, internet browsing. Some wireless communication devices can now also handle voice-over-internet-protocol (VoIP) calls, and others are able to handle multimedia (voice, video, graphics) calls through wireless networks and/or through wireless networks connected to the internet or media servers.
A wireless network operator owns and maintains physical basestations and has licensed frequency spectrum: these are defining properties of a wireless network operator. A ‘virtual wireless network operator’ in contrast has no physical basestations. A ‘virtual wireless network’ (sometimes called a ‘virtual network’) operates with a simple commercial agreement with a wireless network operator; virtual networks operate in the home country of the wireless network that they have an agreement with, basically making use of the Home Location Register (HLR), the billing system and the radio infrastructure of the wireless network but retaining the ability to bill their own customers directly. A Home Location Register (HLR) is a database owned and maintained by a network operator.
Different types of calls, initiated by wireless devices can be restricted for some or most outgoing traffic types; for example, voice and data calls, as well as internet web browsing, can be restricted by the call tariffs made available by the wireless network that is subscribed to. These wireless networks could be operated by a traditional wireless network operator or a virtual network operator. The restrictions can even limit which web servers the user is actually allowed to access; in most or all cases the restrictions will limit the users in their home country to only one wireless network, i.e. the home wireless network to which the user is subscribed to or its associated virtual wireless network.
What is needed is a method that gives users, in particular those users of wireless devices subscribed to a specific wireless network or virtual wireless network in their home country, a choice of the call set-up route(s), and also gives a choice of viewing any desired web server or web-page, and also users to initiate outgoing calls at the tariff of their choice and through any of the wireless network(s) available in their home country (as well as abroad when roaming outside of their home country).
With existing systems however, this is very difficult because mobile network operators have little economic incentive to provide end-users with the freedom to choose the cheapest network for each call set-up route for any outgoing traffic, such as outgoing-SMS, -voice call, -data call. In fact, they have every economic incentive to make this very difficult. One mechanism that entrenches the network operators' ability to restrict such freedom is the fact that every network operator in effect has considerable control over each subscriber because each subscriber with a particular network operator has to be registered in the home location register (HLR) of that operator in order to receive service. The ownership and control that a network operator has over its HLR constitutes a major entry barrier to competitors, especially virtual wireless network operators, seeking to offer lower cost services,
Before summarising the invention, we will explain some background terms.
A Home Location Register (HLR) is a database that is, conventionally, owned and maintained by a wireless network operator. It contains mobile subscriber information for all subscribers to that operator. HLR subscriber information includes the International Mobile Subscriber Identity (IMSI), service subscription information, location information (the identity of the currently serving Visitor Location Register (VLR) to enable the routing of mobile-terminated calls), service restrictions and supplementary services information. The HLR also initiates transactions with VLRs to complete incoming calls and to update subscriber data.
The IMSI is a unique non-dialable number allocated to each mobile subscriber that identifies the subscriber and his or her operator subscription. The IMSI is stored in the Subscriber Identity Module (SIM). The IMSI is made up of three parts: (1) the mobile country code (MCC) consisting of three digits, (2) the Mobile Network Code (MNC) consisting of two digits, and (3) the Mobile Subscriber Identity Number (MSIN) with up to 10 digits.
A Visitor Location Register (VLR) is a database owned and maintained by a wireless mobile operator. It contains temporary information about mobile subscribers that are currently located in a geographic area served by that mobile operator, but whose Home Location Register (HLR) is elsewhere.
When a mobile subscriber roams away from his home location and into a remote location (typically to a different country), SS7 messages are used to obtain information about the subscriber from the HLR, and to create a temporary record for the subscriber in the VLR. There is usually one VLR per operator. The VLR automatically updates the HLR with the new location information, which it does using an SS7 Location Update Request Message. The Location Update Message is routed to the HLR through the SS7 network, based on the global title translation of the IMSI that is stored within the SCCP Called Party Address portion of the message. The HLR responds with a message that informs the VLR whether the subscriber should be provided service in the new location.
The following acronyms are used in this specification:
AuCAuthentication CentreEIREquipment Identity RegisterGMSCSGateway Mobile Switching Centre SwitchHLRHome Location RegisterHLRvnHome Location Register of a virtual networkIF_BWireless Device interfaceIF_CPublic Access Network interfaceIF_DHome Location Register interfaceIF_FServices Mobile Switching Centre Switch interfaceIF-AGMSCS to SMSCS interfaceIF-EMedia Gateway interfaceIMSIInternational Mobile Subscriber IdentityINIntelligent Network sub-moduleLHWNLocal Home Wireless NetworkMGMedia GatewayMSCMobile Switching CentrePANPublic Access NetworkPREPOSBilling and services management for pre and postpaid end-usersPSIMProprietary SIM (includes multiple SIM sub-modules;e.g. a local SIM sub-module and a roaming SIM sub-module, with different IMSI)RANRadio Access NetworkRHWNRoaming Home Wireless NetworkSIMSubscriber Identity ModuleSIMLLocal SIMSIMRRoaming SIMSMSCSServices Mobile Switching Centre SwitchVNVirtual Wireless NetworkWDWireless DeviceWDvnWireless Device using the HLR of a VNWNWireless Network